Combustion chamber shingle of a gas turbine

ABSTRACT

Combustion chamber shingle of a gas turbine, including a bolt for bearing the combustion chamber shingle at the combustion chamber wall, wherein the combustion chamber shingle is formed substantially in a plate-shaped manner, and has at least one bearing element at one side, at which the bolt that is formed as a separate structural element is anchored in a form-locking manner, wherein the bolt, at its end area, is provided with a baring area that is arranged at a rectangular position to the bolt axis and that is arranged inside a recess of the bearing element, wherein the bolt has a centric passageway recess, and wherein the recess of the bearing element is dimensioned so as to be bigger than the baring area of the bolt, so that a hollow space is created between the surface of the combustion chamber shingle and the baring area of the bolt.

The invention relates to gas turbine combustion chambers comprising combustion chamber shingles, wherein combustion chamber shingles are attached to a supporting structure of the external combustion chamber walls.

On the side that is facing the combustion chamber, the combustion chamber shingles have any desired number (which is very high, often comprising several thousands) of effusion cooling holes. These effusion cooling holes serve for cooling the shingle in order to counteract the high temperatures inside the combustion chamber. Further, a combustion chamber shingle has at least one mixed air hole through which air from the space externally surrounding the combustion chamber (annular channel/annulus) is guided inside the combustion chamber so as to cool down and to lean the combustion and thus to reduce the NOx formation inside the combustion chamber. In addition to cooling through the effusion cooling holes, the shingles are often provided with a ceramic coating that serves as an insulating layer against the high temperatures present inside the combustion chamber

This configuration is known from the state of the art, see EP 972 992 B1 or DE 102 14 570 A1, for example.

FIG. 2 shows a schematic representation of a combustion chamber 15. The combustion chamber 15 comprises a fuel nozzle 29 that is mounted at a combustion chamber head in the usual manner. Further, an external combustion chamber housing 30 as well as an internal combustion chamber housing 31 are provided. A combustion chamber wall 32 encloses the actual combustion chamber 15 and supports combustion chamber shingles 34. The reference sign 33 schematically shows a turbine inlet guide vane row. Air is supplied in the usual manner through mixed air holes 35. The inflow direction is indicated by the reference sign 36.

FIG. 3 shows a shingle 34 with effusion cooling holes 37 according to the state of the art. The geometry (diameter, shape) of a mixed air hole 35 can be embodied in a suitable manner, as is known from the state of the art. The same applies to the size and arrangement of the effusion cooling holes 37. The formation of the mixed air holes 35 is often carried out in such a manner that they are constructionally formed like a funnel or a duct that projects into tie combustion chamber 15.

The shingles 34 are usually manufactured either by means of casting, coating with a ceramic layer and drilling of the effusion cooling holes 37 (e.g. by using laser), or by casting, drilling and coating, or an additive manufacturing process such as selective laser sintering, direct laser depositioning or electron beam deposition welding, for example. In the additive methods, the effusion cooling holes 37 are inserted directly into the shingle 34 and the elaborate drilling process is eliminated.

During operation, there is a constant occurrence of problems with the so-called creeping of the material, which may lead to failure of the threaded pin and thus to a loss of the shingle.

Moreover, when it comes to the construction of the shingle with an integrated threaded pin, it is suited for an additive manufacturing method such as selective laser sintering, direct laser depositioning or electron beam deposition welding only to a limited degree, since either the cost-intensive horizontal manufacturing has to be chosen or an elaborate substructure for supporting the setscrew has to be provided. Such a substructure has substantial disadvantages. It is a) material-intensive, b) it changes the manufacturing process and c) it has to be removed from the shingle after the manufacture. This is very cost-intensive.

The invention is based on the objective to create a combustion chamber shingle of a gas turbine and a mounting option of such a combustion chamber; which has a simple structure and can be manufactured in a simple, cost-effective way while also avoiding the disadvantages of the state of the art and ensuring good mountability.

According to the invention, the objective is solved by the combination of the features of claim 1, with the subclaims showing further advantageous embodiments of the invention.

Thus, it is provided according to the invention that the shingle is formed in a substantially plate-shaped manner and that it has at least one bearing element at one side (namely at the side that is facing the combustion chamber wall) which is formed as an integral piece at the shingle. The bearing element is formed in such a way that a bolt, which is manufactured as a separate structural element, can be anchored or attached at it in a form-locking manner.

Thus, the combustion chamber shingle according to the invention is embodied in such a manner that a separate bolt, which can be a threaded bolt or a bolt that is to be attached with a securing element according to the invention, is anchored at the shingle in a form-locking manner. Thus, it is possible according to the invention to manufacture the bolt from a different material than the shingle. Further it is possible to choose a simple and cost-effective manufacturing method for the shingle, since the bolt can be manufactured as a separate structural element. Particularly through the possibility to use different material for the shingles and the bolts, it is possible to solve the fastening problems known from the state of the art and to prevent or to minimize any creeping of the bolt material.

According to the invention it is preferably provided that at its end area the bolt is furnished with a baring area which is arranged in a rectangular position to the bolt axis and that is arranged in a recess of the bearing element. The bolt is thus formed in a way that is similar to a hook, and it is inserted into the recess of the bearing element. Here, the baring area of the bolt can be dimensioned in a suitable manner, for example so as to be plate-shaped or so as to have any other cross section, for example a round, oval, square or a rectangular one. Thus, the combustion chamber shingle has a seating for bolts through the bearing element and the recess that is provided therein, so that the bolt can be hung into the shingle in a form-locking manner. Here, it is possible according to the invention to receive the baring area in the recess with or without a clearance, particularly in order to make allowance for different thermal expansions, or the like.

The recess of the bearing element is formed in such a manner that the baring area of the bolt can be inserted laterally. In order to avoid that the baring area of the bolt slips out of the recess of the bearing element, it can be advantageous to provide several such bearing elements at the shingle in the further development of the invention, with the recesses of the bearing elements opening towards different directions. In this way, any unfastening of the bolt is avoided.

The bolt according to the invention is usually inserted through a hole of the external combustion chamber wall in the usual manner, so that the actual fastening of the bolt is substantially not different from the state of the art. Thus, it is possible to screw on a nut to a threaded bolt in the usual manner.

The embodiment according to the invention also makes it possible to support the shingle against the combustion chamber wall, or to make the shingle directly abut the combustion chamber wall in an alternative embodiment. Thus, different cooling concepts can be embodied in a manner as it is also known from the state of the art.

Further it is possible according to the invention to form the external contour of the bearing element, which is fastened at the combustion chamber shingle, in a streamlined manner, for example to provide it with slanted shoulders. Also, effusion cooling holes can be formed in the bearing element according to the invention in order to ensure the cooling of the combustion chamber shingle.

Thus, it is provided according to the invention that the bolt has a centric passageway opening through which cooling air can be introduced. In this way, a reliable and effective cooling of the bolt is achieved, so that the thermal problems (creeping of the material), as they are known form the state of the art, are avoided. Further, the recess of the bearing element is formed and dimensioned in such manner, that when the bolt is mounted or the combustion chamber shingle is mounted a hollow space is created between the baring area of the bolt and the surface of the combustion chamber shingle through which the cooling air streams. That, too, leads to a particularly good cooling effect.

In a further development of the invention it is also provided that the bearing element is furnished with additional cooling holes. These can be formed as impingement cooling holes in order to provide additional cooling for the bottom area of the bolt and its baring area.

The bolt according to the invention comprising the baring area formed at it can be cast, milled or manufactured by means of an additive method.

According to the invention, the combustion chamber shingle is formed in such a way that it is producible by means of an additive method. Such additive methods may be selective laser sintering, direct laser depositioning (DLD) or electron beam deposition welding, for example. Here, the shingle can be manufactured in such a manner that neither a cost-intensive horizontal manufacturing process nor an elaborate substructure is necessary. Thus, the shingle can be manufactured in a cost-effective and simple manner.

In the following, the invention is described by using exemplary embodiments in connection to the drawing. Herein:

FIG. 1 shows a schematic representation of a gas turbine engine according to the present invention,

FIG. 2 shows a schematic side view (in a sectional representation) of a combustion chamber according to the state of the art,

FIG. 3 shows a top view and a side view of a combustion chamber shingle as known from the state of the art,

FIG. 4 shows a sectional side view of a mounting option of a combustion chamber shingle at the external combustion chamber wail according to the state of the art,

FIG. 5 shows a simplified schematic top view of a shingle comprising bearing elements for a baring area of a bolt according to the invention,

FIG. 6 shows a schematic side view of a shingle, which is mounted at a combustion chamber wall in a manner according to the invention,

FIG. 7 shows side views and top views of different embodiment variants of bolts comprising baring areas,

FIG. 8 shows different embodiment variants of bolts comprising bearing areas as well as of bearing elements comprising pocket-like recesses,

FIG. 9 shows different embodiment variants in side view and top view,

FIG. 10 shows a simplified side view, analogous to FIG. 6, in the mounted state,

FIG. 11 shows a partial perspective view of bearing elements comprising cooling holes, and

FIG. 12 shows a variety of embodiment variants for bearing elements according to the invention in the partial perspective view.

The gas turbine engine 10 according to FIG. 1 is an example of a turbomachine in which the invention may be used. However, it becomes clear from the following that the invention can also be used in other turbomachines. The engine 10 is embodied in a conventional manner and comprises, arranged in succession in the flow direction, an air inlet 11, a fan 12 that is circulating inside a housing, a medium-pressure compressor 13, a high-pressure compressor 14, combustion chambers 15, a high-pressure turbine 16, a medium-pressure turbine 17 and a low-pressure turbine 18 as well as an exhaust nozzle 19, that are all arranged around a central engine axis 1.

The medium-pressure compressor 13 and the high-pressure compressor 14 respectively comprise multiple stages, each of which has an array of fixedly attached, stationary guide blades 20 extending in the circumferential direction, which are generally referred to as stator blades and protrude radially inwards from the engine cowling 21 through the compressors 13, 14 into a ring-shaped flow channel. The compressors further have an array of compressor rotor blades 22 that protrude radially outwards from a rotatable drum or disc 26 coupled with hubs 27 of the high-pressure turbine 16 or the medium-pressure turbine 17.

The turbine sections 16, 17, 18 have similar stages, comprising an array of fixedly attached guide blades 23 that protrude radially inward from the housing 21 through the turbines 16, 17, 18 into the ring-shaped flow channel, and a subsequent array of turbine blades 24 that protrude outward from a rotatable hub 27. During operation, the compressor drum or the compressor disc 26 and the blades 22 arranged thereon as well as the turbine rotor hub 27 and the turbine blades 24 arranged thereon rotate around the central engine axis 1.

FIG. 4 shows different side views according to the state of the art, in which a support 41 of the combustion chamber shingle 34 against the combustion chamber wall 32 is illustrated.

FIG. 5 shows a simplified top view of the combustion chamber shingle 34 according to the invention. At that combustion chamber shingle 34, namely at its edge, edge boards 51 are provided, which are formed in the shape of a web-like edge, as can also be seen in FIG. 6. In the four corners of the combustion chamber shingle 34 one bearing element 40 is provided, respectively, which is furnished with a slit-like or pocket-like recess 44. It can be seen that the opening directions of the recesses 44 have different orientations, so that even if the nuts 39 become unfastened inserted bolts 38 cannot slip out in the mounted state, since the bolts 38 are positioned in the recesses or bores of the corresponding combustion chamber wall 32. In the central area of FIG. 5, another bearing element 40 is arranged.

FIG. 6 shows a mounted side view, analogous to the rendering of FIG. 5, in a strongly simplified form.

FIG. 7 shows bolts 38 which are respectively provided with one thread in the upper and lower row. They have respectively one centric passageway recess 48 in the shape of a hole, through which cooling air from the passageway recess can be passed. As is apparent form the illustrations of FIG. 7, each bolt 38 is provided with a baring area 47 that is oriented perpendicular to the bolt's central axis, with the baring area 47 being insertable into a suitable recess 44 of the bearing element 40, in the way it is shown in FIG. 10. It also follows from FIG. 7 that different shapes of baring areas 47 can be provided, namely round, square, rectangular, rounded or trapezoid ones. Other shapes are also possible. Further, FIG. 7 shows that the baring area 47 can be provided with at least one cooling air hole 50 for cooling the baring area 47 and thus the bottom area of the bolt 38.

FIG. 8 shows a variety of embodiment variants of bolts 38 comprising baring areas 47, analogous to the renderings of FIG. 7. In addition, corresponding bearing elements 40 with suitable recesses 44 are shown. The bearing elements 40 can also be provided with cooling holes 52. It follows that the recesses 44 of the bearing elements 40 are respectively dimensioned in such a manner that the bolts 38 can be laterally inserted with the baring areas 47.

Ensuing from FIG. 9 are various embodiment variants in the mounted state, wherein it is particularly apparent how the baring areas 47 are respectively inserted into the slit-like or pocket-like recesses 44 of the bearing elements 40. Here, the baring areas 47 abut the upper legs or the surfaces of the bearing elements 40, so that below the baring areas 47 respectively one hollow space 49 is formed, into which cooling air is supplied, namely on the one hand through the passageway recess 48 of the bolt 38 and on the other hand through additional cooling holes 52. There are also lateral recesses 53 which serve to provide a through-flow of cooling air and which are shown in the two embodiment variants that are depicted on the bottom right of FIG. 9.

FIG. 10 shows, in a simplified sectional view, a mounted state of the bolt 38 according to the invention with its baring area 47 inside a recess 44 of the bearing element 40. Here, too, the hollow space 40 is once more illustrated, which is filled with cooling air. In addition, cooling air can also flow through effusion cooling holes 37.

FIG. 11 shows another embodiment variant, in which the baring areas 40 are furnished with laterally cooling holes 52, respectively, which are provided in rows or in regularly distributed arrangements in order to introduce cooling air to the bottom area of the bolt 38.

FIG. 12 again shows possible embodiments of bearing elements 40 in different partial perspective views. What follows here is that these can be formed in a bell-like or bow-like manner, and that they have a lateral slit or a lateral opening for inserting the bolt 38.

PARTS LIST

1 engine axis

10 gas turbine engine

11 air inlet

12 fan rotating in a housing

13 medium-pressure compressor

14 high-pressure compressor

15 combustion chamber

16 high-pressure turbine

17 medium-pressure turbine

18 low-pressure turbine

19 exhaust nozzle

20 guide blades

21 engine cowling

22 compressor rotor blades

23 guide blades

24 turbine blades

26 compressor drum or compressor disc

27 turbine rotor hub

28 outlet cone

29 fuel nozzles

30 external combustion chamber housing

31 internal combustion chamber housing

32 combustion chamber wall

33 turbine inlet guide vane row

34 combustion chamber shingle

35 mixed air hole

36 inflow direction

37 effusion cooling hole

38 bolt

39 nut

40 bearing element

41 support

43 thread

44 recess

45 slit

46 bolt axis

47 bearing element

48 passageway recess

49 hollow space

50 cooling hole

51 edge board/shingle side board

52 cooling hole

53 recess 

1. A combustion chamber shingle of a gas turbine, comprising a bolt for bearing the combustion chamber shingle at the combustion chamber wall, wherein the combustion chamber shingle is formed substantially in a plate-shaped manner, and has at least one bearing element at one side, at which the bolt that is formed as a separate structural element is anchored in a form-locking manner, wherein the bolt, at its end area, is provided with a baring area that is arranged at a rectangular position to the bolt axis and that is arranged inside a recess of the bearing element, wherein the bolt has a centric passageway recess, and wherein the recess of the bearing element is dimensioned so as to be bigger than the baring area of the bolt, so that a hollow space is created between the surface of the combustion chamber shingle and the baring area of the bolt.
 2. The combustion chamber shingle according to claim 1, wherein the bearing element is provided with cooling holes.
 3. The combustion chamber shingle according to claim 1, wherein the recess of the bearing element is opened up laterally.
 4. The combustion chamber shingle according to claim 1, wherein the bearing element is formed in a bow-like or bell-like manner.
 5. The combustion chamber shingle according to claim 1, wherein the bolt can be inserted into the recess with the baring area in a direction perpendicular to the bolt axis of the bolt.
 6. The combustion chamber shingle according to claim 1, wherein, at the combustion chamber shingle, multiple bearing elements are formed, that have recesses which are formed in such a manner that they are opened towards different directions.
 7. The combustion chamber shingle according to claim 1, wherein the bearing element and/or the combustion chamber shingle is provided with effusion cooling holes in the area of the bearing element.
 8. The combustion chamber shingle according to claim 1, wherein the baring area is formed in a plate-shaped or bar-shaped manner.
 9. The combustion chamber shingle according to claim 1, wherein the bearing element is integrated in an edge board of the combustion chamber shingle.
 10. The combustion chamber shingle according to claim 1, wherein the bolt is formed as a threaded bolt. 